The following publications are believed to represent the current state of the art:
Kobus Barnard et al., Matching words and pictures, Journal of Machine Learning Research, 3, 2003.
D L Duffy et al. A three-single-nucleotide polymorphism haplotype in intron 1 of OCA2 explains most human eye-color variation. Am J Hum Genet.; 80(2):241-52. 2007.
K. Chase, D. R. Carrier, F. R. Adler, T. Jarvik, E. A. Ostrander, T. D. Lorentzen, and K. G. Lark. Genetic basis for systems of skeletal quantitative traits: Principal component analysis of the canid skeleton. PNAS, 99:9930-9935, July 2002.